In　recent　years,　the　accident　rate　of　urban　rail　transit　PPP　(public-private　partnerships)　project　under　construction　has　been　relatively　high,　and　the　issue　of　security　risks　has　attracted　great　attention　from　all　walks　of　life.　Therefore,　it　is　necessary　to　identify,　analyze,　and　evaluate　the　issue　of　security　risks　of　the　urban　rail　transit　PPP　project.　This　paper　takes　the　PPP　project　of　urban　rail　transit　as　the　object.　Through　offline　interviews　and　surveys　and　online　questionnaires,　this　paper　focuses　on　identifying　and　analyzing　the　risks　brought　by　the　introduction　of　PPP　mode　to　the　urban　rail　transit　project　and　its　action　mechanism.　The　risk　evaluation　method　based　on　Bayesian　network　model　is　studied,　which　is　described　from　three　dimensions:　risk　occurrence　probability,　risk　reasoning,　and　risk　sensitivity.　Finally,　an　example　of　Xuzhou　Metro　Line　3　is　given　to　verify　the　feasibility　of　the　proposed　method.　This　study　provides　a　reference　basis　for　relevant　practitioners　and　promotes　the　healthy　development　of　the　industry.